Digitaria ischaemum is very close to D. violascens, but has a slightly stouter habit with broader leaves, a few short, widely spreading racemes, and larger, plumper spikelets. It also has a more temperate distribution.

Digitaria ischaemum, D. fauriei, D. longiflora, and D. violascens belong to a group of Digitaria known as the Verrucipilae because of their warty spikelet hairs. A compound microscope is required to see this, but the hairs have a beadlike appearance under moderate magnification. These spikelet hairs also have curled tips in D. ischaemum (and sometimes in D. violascens), which led to the hairs being described as capitate or clavate in the past.